Since the beginnings of wired (and later wireless) communications, an implicit goal of the communication whether it was telegraphy, telephony, television or the various versions of "video-phone", was to bring the participants at the ends of the communication as "close together" as possible. This is also the goal of traditional teleconferencing systems. Ideally, the effect obtained in good communication should be one of "being there". Presently, efforts are being directed to the development of teleconferencing systems that are suited for casual and spontaneous communication, rather than scheduled communications.
To contrast casual and scheduled communications, one might use the traditional teleconferencing experience as an example of a scheduled interchange. Participants are generally known to each other (and are often collaborating) well in advance of their use of the teleconference facility. They make arrangements to participate in a teleconference on a specific day, at a specific time, usually to avoid physical travel between their respective locations. Casual or spontaneous communications occur on the other hand, when two or more persons meet with each other on an unplanned informal basis.
The traditional teleconference facility is generally a shared, extremely high cost facility (one reason for its tightly scheduled usage). The facility itself puts extreme limitations on the normal human protocols for interaction. Most facilities offer some version of NTSC (home television like) video display on relatively small sized monitors. When the number of teleconference participants at a sending end of a conference is larger than one, the image of each participant occupies a small portion of an already small viewing area. As a result, it becomes difficult for viewers at the receiving end of such an image to pick up non-verbal cues from the speaker's face and body. Indeed, in many cases it is often difficult to discern who of the many participants is actually speaking.
The audio in most teleconference facilities has been of the half-duplex (one direction at a time) type. An "audio gate" determines the instantaneous direction of transmission. Generally the loudest noise source at the two ends of the conference determines the originating end of the link. The reason for the simplex operation is to prevent feedback from the speakers to the microphones at each end of the conference. Although the gated half-duplex link is effective in preventing feedback it causes several problems. First, it prevents speakers at one end of a teleconference from being able to interrupt speakers at the other end and simultaneously hear the results of their own interrupt. Another problem is that any loud and unplanned noise at one end (sneezing, the ruffling of papers, a book falling to the floor) will often gate the conversation path in the wrong direction. Since all participants of the teleconference generally understand the problem, they begin to try to accommodate to it and speak in an unnatural and chopped mode instead of the usual free flow conversational mode of interaction.
It is an object of the present invention to provide a teleconferencing system which overcomes the problems or prior art teleconferencing systems and which enables groups of participants at both ends of a teleconference link to casually communicate. It is a further object of the present invention to provide a high resolution video display for use in connection with the teleconferencing system and special camera arrangements for implementing the high resolution video display.